I've found that I can make sufficient smoke using wet wood chips by laying out aluminum foils, placing wood chips in a thin line, and rolling the foil to the width and height of the space around the left rear of the grill - making sure to leave the ends of the foil open to allow the smoke to escape. They must be of sufficient width to prevent dropping down, yet narrow enough that the grid sits down level on top.

I make one to go on the space that runs along the back of the grill, and one for the space that runs along the left side of the grill. The wrapped foil is kinda an inverted "L".

The 1st attempt, the heat burned through the foil and I nearly dropped the ash and wood remnants down into the cavity where the burner is. I fixed this by folding a length of foil over several times and using this as a liner to lay the soaked chips on.